Is this an existing campaign? Or are you just coming up with ideas for a new one? Can you tell us anything about what you're looking for (maybe give some ideas you've already had and why they aren't what you're looking for)?

Arcana Rising is a modern or near future urban fantasy setting powered by an OSR based ruleset. I believe you could slot some of the ickier horrors from, say, Lamentations of the Flame Princess into its mechanical framework.